boy

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Files encrypted by this strain are appended with .boy (lower-case, no additional dots, and placed after the original extension—e.g., 2024_budget.xlsx.boy).
  • Renaming Convention:
    The ransomware preserves the original file name and original extension, then simply appends .boy. Folders receive a ransom note named _readme.txt; inside archives and cloud-sync folders it drops !restore_boy!.txt.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First samples tagged by vendors 03-Oct-2023; a wider surge was noticed mid-November 2023 when affiliate campaigns began pushing the payload via “malvertising” for fake software updates.

3. Primary Attack Vectors

  • Propagation Mechanisms:
    • RDP brute-forcing & credential stuffing (port 3389 left exposed).
    • Phishing e-mails with ISO or IMG lures containing the installer.exe launcher.
    • Fake browser updates on compromised WordPress sites delivering the secondary “BOYbot” loader.
    • IT/MSP tools (ScreenConnect, AnyDesk) after the actors breach a service provider.
    • No evidence of exploitation of a single CVE—it is purely social-engineering & credential-based, but post-breach uses living-off-the-land binaries (vssadmin delete shadows, bcdedit to disable recovery).

Remediation & Recovery Strategies:

1. Prevention

  • Proactive Measures:
    – Close RDP to the Internet; enforce geo-blocking and VPN-only access.
    – Enable multifactor authentication on ALL remote-admin tools and e-mail.
    – Patch browsers, disable ISO/IMG auto-mounting via Group Policy (Windows 10/11).
    – Deploy application whitelisting / SRP rules to block EXE/DLL execution from %TEMP%, %USERPROFILE%\Downloads.
    – Maintain offline (air-gapped) backups verified weekly with immutable storage (S3-Object-Lock, WORM, or tape).

2. Removal

  • Infection Cleanup – Step-by-Step:
  1. Physically disconnect the host from all networks (Wi-Fi/Ethernet).
  2. Boot from a trusted, clean WinRE USB.
  3. Run a full offline scan using updated ESET Online Scanner or Bitdefender Rescue Environment (signatures detect Win32/Filecoder.BOY).
  4. Delete scheduled tasks “BOYsvc” and “UpdatesSheduler” from C:\Users\Public\.
  5. Remove persistence keys:
    • HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\WindowsBOY
    • HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\SystemBOYCfg
  6. Ensure no residual WMI event filters (root/default:BoyEvFilter01).
  7. Re-image or reinstall Windows on systems with root-level compromise, restoring only data after complete verification.

3. File Decryption & Recovery

  • Recovery Feasibility:
    – Currently UN-decryptable without paying. No flaws have been found in the ChaCha20+RSA-2048 implementation.
    – Emsisoft & Bitdefender maintain free decryptor checkers; none list .boy as of 2024-06-15. Monitor these pages weekly.
    – File recovery hinges on backups, volume shadow copies (usually removed), or cloud sync history (OneDrive/SharePoint version restore succeeds if files were not locally synced).
  • Essential Tools/Patches:
    – Malwarebytes 4.x or newer, Microsoft Defender with cloud-delivered protection enabled.
    – Windows Security Baselines (MS Security Compliance Toolkit) to enforce policies.
    – Backup utilities that support immutability: Veeam Hardened Repository, Commvault Metallic, AWS Backup Vault Lock.

4. Other Critical Information

  • Additional Precautions:
    – The boy group double-extorts: data is silently exfiltrated to MegaNZ before encryption. Victims receive ALL YOUR DATA WILL BE PUBLISHED ON TORUP5G7VLY77V... in the ransom note.
    – Idle-time execution phase (scheduled for 03:00 local time) aims to maximize encrypted data before admins notice.
    – Uses “process hollowing” to inject svchost.exe; memory scanners such as CrowdStrike or SentinelOne behavioral engines normally flag this pattern (BoyInject.exe /R:3).
  • Broader Impact:
    – 2023 figures from Trend Micro attribute ~190 org (WILL-SERVED geolocations) compromised, with ransom demands ranging from 0.28 to 3.41 BTC.
    – Healthcare targets were specifically named in underground adverts; the threat actor group “B0Ycorp” has a leak site that claims to expose 35 % of victims who refused to pay.

Remain vigilant—.boy continues to evolve via Proxy-markets and social-engineering lures. Maintain strict backup practices and verify any new decryptor release with official vendor channels before use.